__be16 id;
u8 protocol;
u8 ecn; /* RFC3168 support */
+ u16 max_df_size; /* largest frag with DF set seen */
int iif;
unsigned int rid;
struct inet_peer *peer;
{
return user == IP_DEFRAG_AF_PACKET ||
ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_IN,
- __IP_DEFRAG_CONNTRACK_IN_END);
+ __IP_DEFRAG_CONNTRACK_IN_END) ||
+ ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_BRIDGE_IN,
+ __IP_DEFRAG_CONNTRACK_BRIDGE_IN);
}
/*
{
struct sk_buff *prev, *next;
struct net_device *dev;
+ unsigned int fragsize;
int flags, offset;
int ihl, end;
int err = -ENOENT;
if (offset == 0)
qp->q.flags |= INET_FRAG_FIRST_IN;
+ fragsize = skb->len + ihl;
+
+ if (fragsize > qp->q.max_size)
+ qp->q.max_size = fragsize;
+
if (ip_hdr(skb)->frag_off & htons(IP_DF) &&
- skb->len + ihl > qp->q.max_size)
- qp->q.max_size = skb->len + ihl;
+ fragsize > qp->max_df_size)
+ qp->max_df_size = fragsize;
if (qp->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
qp->q.meat == qp->q.len) {
head->next = NULL;
head->dev = dev;
head->tstamp = qp->q.stamp;
- IPCB(head)->frag_max_size = qp->q.max_size;
+ IPCB(head)->frag_max_size = max(qp->max_df_size, qp->q.max_size);
iph = ip_hdr(head);
- /* max_size != 0 implies at least one fragment had IP_DF set */
- iph->frag_off = qp->q.max_size ? htons(IP_DF) : 0;
iph->tot_len = htons(len);
iph->tos |= ecn;
+
+ /* When we set IP_DF on a refragmented skb we must also force a
+ * call to ip_fragment to avoid forwarding a DF-skb of size s while
+ * original sender only sent fragments of size f (where f < s).
+ *
+ * We only set DF/IPSKB_FRAG_PMTU if such DF fragment was the largest
+ * frag seen to avoid sending tiny DF-fragments in case skb was built
+ * from one very small df-fragment and one large non-df frag.
+ */
+ if (qp->max_df_size == qp->q.max_size) {
+ IPCB(head)->flags |= IPSKB_FRAG_PMTU;
+ iph->frag_off = htons(IP_DF);
+ } else {
+ iph->frag_off = 0;
+ }
+
IP_INC_STATS_BH(net, IPSTATS_MIB_REASMOKS);
qp->q.fragments = NULL;
qp->q.fragments_tail = NULL;